Here is an article on using laminar airflow to get better cutting results. The project is on Hackaday now.
Anybody want to adapt the idea for our laser?
I have succeeded in making a prototype nozzle. It seems like it would work. I need to try printing it with a resin printer so I can see how it works without internal stringing. Any volunteers?
I could try it but can't promise a quick turnaround. I haven't fired up my resin printer and gone through that learning curve yet. Maybe a week or two if noone else can take it on?
It looks to me like you could make a machined version of this by bundling a group of thin walled brass tubes, then soldering them all together. Larger one in the middle to pass the laser, and small ones all around to flow the air. Then it would be pretty easy to turn the bundle to shape on the lathe. If you blocked the end of the large "laser passing" tube with a thin ZnSe window (available from ebay... essentially an IR lens, but flat instead of curved) you could get the effect the article talks about where the center is blocked and the outer tubes provide all of the flow.
The internal nozzle structure is the pointy bit. I don't have the mad solder skills to make that happen. I have been trying to gradually change the diameter of the tubes to get a lamanar air flow while increasing the air velocity.